Copper Sulphate (CuSO4) Solution as a Fungiside ?

[SouthPark]

Originally Posted by Ray

I think the important part is the elemental copper, which in copper sulfate pentahydrate, is 25.975%, making Physan 25.975% of 213.6 or 5.54%.

Whether copper sulfate, copper acetate, copper hydroxide, or whatever other copper compound is used, it's the copper concentration that's important.

Thanks Ray! That helps a lot. I'll keep that in mind about the copper content being most important here.

Some online work was done to find the copper content being that value you got ---- which was approx 25.45% copper in copper sulphate pentahydrate. That's very close to your value (as is the resulting 5.44 percent copper in phyton 27 liquid).

Based on percentage copper in phyton 27, the same formula can be used to get the amount of phyton 27 to add to 'W' litres of freshwater to make up an orchid-safe solution containing 0.3 percent of the 5.44 percent copper (ie. a final copper concentration of 0.01632 percent copper in orchid safe solution).

W = 0.5 litre of freshwater to be used for making orchid-safe copper solution (changeable value)
Y = copper concentration in phyton 27 = 5.44 % (fixed value)
D = desired orchid-safe copper concentration = 0.01632 % (normally fixed value)

x = (D.W)/(Y-D) = (0.01632 * 0.5) / (5.44 - 0.01632)

x = 0.0015 litre or 1.5 mL (of phyton 27 liquid to be added to 0.5 L of freshwater).

To make things really easy, the calculation just boils down to:

x = W * 0.003

With 'W' being the amount of freshwater we'll be using.

So if W = 2 litre of freshwater, then we have to add x = 0.006 L or 6 mL of phyton 27 to 2 litres of freshwater.